thiserror VS anyhow

Inspired by this blog post I just added an `#[implicit]` field feature to the `thiserror` crate. It makes it easy to automatically annotate errors with things like code location (per this blog post), a timestamp, or a backtrace without requiring further modifications to the thiserror crate. I'm hoping that dtolnay will consider it. You can find my PR here: https://github.com/dtolnay/thiserror/pull/402

We can utilize third-party libraries to simplify the code above. For example thiserror (https://github.com/dtolnay/thiserror) provides convenien derive macro for Error trait:

thiserror crate makes it easy to do so using macros on CliError enum.

Depending on your use case, thiserror and/or anyhow.

What is the benefit of splitting a proc-macro crate into (usually) two crates, proc_macro_crate and proc_macro_crate_impl? Why not just have one crate? Does it offer any benefits to to overall compilation times? An example of this can be seen in the thiserror crate where there's a thiserror and thiserror_impl crate.

You might want to use thiserror to generate implementation for Error and Display.

thiserror for my error types.

thiserror - https://crates.io/crates/thiserror

I dont think you realize how ridiculous this comment is. Youre comparing 10 lines of Go, with 200 of Rust:

https://github.com/dtolnay/thiserror/blob/master/src/lib.rs

Couple of questions, which are because of my limited knowledge.

1) The pointer provenance you're referring to, is that CHERI or the pointer provenance currently in use in macOS?

2) Reading through your post, are you talking about the same as the anyhow's error implementation? https://github.com/dtolnay/anyhow/blob/af0937ef72fbaf9784a6c...

Depending on your use case, thiserror and/or anyhow.

There is ? as well as the anyhow(https://github.com/dtolnay/anyhow) crate that deals with long nested result chains.

There are crates out there that help you reduce this boiler plate. thiserror is good for creating custom errors and color-eyre or anyhow are good for dynamic errors.

Give anyhow a look.

I've brought anyhow::Result into scope, making error handling super easy to use. We don't need to specify all our Error types. It can automatically convert any errors that implement std::error::Error, which should be all of them. If an error propagates all the way up to main(), we'll get all the info it's captured printed to stdout.

Alternatively, if you've got a lot of error types and you're outside a library (so directly in a binary where you don't plan to reuse code elsewhere) you can use anyhow. This gives you an error type you can basically propagate any other error through. On top of that you can attach context information at every return. It's basically a more complicated Result>.

One approach is to define a separate error type for each crate and then use anyhow, eyre or Box to wrap the error, whever a function can return errors originating in several different crates.